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From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Joerg Roedel <jroedel@suse.de>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	Chester Lin <clin@suse.com>, Juergen Gross <jgross@suse.com>
Subject: [PATCH 01/24] x86/traps: Remove stack-protector from traps.c
Date: Wed,  1 Sep 2021 01:50:02 +0800	[thread overview]
Message-ID: <20210831175025.27570-2-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20210831175025.27570-1-jiangshanlai@gmail.com>

From: Lai Jiangshan <laijs@linux.alibaba.com>

When stack-protector is enabled, the compiler adds some instrument code
at the beginning and the end of some functions. Many functions in traps.c
are non-instrumentable.  Moreover, stack-protector code in the beginning
of the affected function accesses the canary that might be watched by
hardware breakpoints which might also violate the non-instrumentable
nature of some functions.

So it is better to remove stack-protector from traps.c.

It is also prepared for later patches that move some entry code into
traps.c, some of which can NOT use percpu register until gsbase is
properly switched.  And stack-protector depends on the percpu register
to work.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
 arch/x86/kernel/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 3e625c61f008..21aa164cece2 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -48,6 +48,9 @@ KCOV_INSTRUMENT		:= n
 
 CFLAGS_head$(BITS).o	+= -fno-stack-protector
 
+CFLAGS_REMOVE_traps.o		= -fstack-protector -fstack-protector-strong
+CFLAGS_traps.o			+= -fno-stack-protector
+
 CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace
 
 obj-y			:= process_$(BITS).o signal.o
-- 
2.19.1.6.gb485710b


  reply	other threads:[~2021-08-31 17:50 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31 17:50 [PATCH 00/24] x86/entry/64: Convert a bunch of ASM entry code into C code Lai Jiangshan
2021-08-31 17:50 ` Lai Jiangshan [this message]
2021-08-31 17:50 ` [PATCH 02/24] x86/traps: Move arch/x86/kernel/traps.c to arch/x86/entry/ Lai Jiangshan
2021-09-02  8:09   ` Joerg Roedel
2021-09-02  9:21     ` Lai Jiangshan
2021-09-02 10:50       ` Peter Zijlstra
2021-09-02 11:54         ` Lai Jiangshan
2021-09-02 12:05           ` Peter Zijlstra
2021-09-02 13:34             ` Peter Zijlstra
2021-09-02 17:05               ` Nick Desaulniers
2021-09-02 17:19                 ` Miguel Ojeda
2021-09-02 17:23                   ` Nick Desaulniers
2021-09-03  7:36                 ` Martin Liška
2021-09-07 21:12                   ` Nick Desaulniers
2021-09-08  7:33                     ` Martin Liška
2021-08-31 17:50 ` [PATCH 03/24] x86/traps: Move declaration of native_irq_return_iret up Lai Jiangshan
2021-08-31 17:50 ` [PATCH 04/24] x86/entry: Expose the address of .Lgs_change to traps.c Lai Jiangshan
2021-09-02  9:14   ` Peter Zijlstra
2021-09-02  9:20     ` Lai Jiangshan
2021-08-31 17:50 ` [PATCH 05/24] x86/entry: Introduce __entry_text for entry code written in C Lai Jiangshan
2021-08-31 19:34   ` Peter Zijlstra
2021-09-01  0:23     ` Lai Jiangshan
2021-08-31 17:50 ` [PATCH 06/24] x86/entry: Move PTI_USER_* to arch/x86/include/asm/processor-flags.h Lai Jiangshan
2021-08-31 17:50 ` [PATCH 07/24] x86: Mark __native_read_cr3() & native_write_cr3() as __always_inline Lai Jiangshan
2021-08-31 17:50 ` [PATCH 08/24] x86/traps: Add C verion of SWITCH_TO_KERNEL_CR3 as switch_to_kernel_cr3() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 09/24] x86/traps: Add fence_swapgs_{user,kernel}_entry() Lai Jiangshan
2021-09-02  9:25   ` Peter Zijlstra
2021-08-31 17:50 ` [PATCH 10/24] x86/traps: Move pt_regs only in fixup_bad_iret() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 11/24] x86/entry: Replace the most of asm code of error_entry to C code Lai Jiangshan
2021-09-02 10:16   ` Peter Zijlstra
2021-09-02 12:08     ` Lai Jiangshan
2021-08-31 17:50 ` [PATCH 12/24] x86/traps: Reconstruct pt_regs on task stack directly in fixup_bad_iret() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 13/24] x86/traps: Mark sync_regs() and fixup_bad_iret() as static __always_inline Lai Jiangshan
2021-08-31 17:50 ` [PATCH 14/24] x86/entry: Make paranoid_exit() callable Lai Jiangshan
2021-08-31 17:50 ` [PATCH 15/24] x86/entry: Call paranoid_exit() in asm_exc_nmi() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 16/24] x86/entry: Use skip_rdi instead of save_ret for PUSH_AND_CLEAR_REGS Lai Jiangshan
2021-08-31 17:50 ` [PATCH 17/24] x86/entry: Introduce struct ist_regs Lai Jiangshan
2021-09-10  0:18   ` Lai Jiangshan
2021-09-10  0:36     ` Lai Jiangshan
2021-09-10  4:31     ` H. Peter Anvin
2021-09-10  7:13       ` Lai Jiangshan
2021-09-10  7:14         ` H. Peter Anvin
2021-09-10  4:50     ` H. Peter Anvin
2021-09-10  4:51       ` H. Peter Anvin
2021-08-31 17:50 ` [PATCH 18/24] x86/entry: Add the C version ist_switch_to_kernel_cr3() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 19/24] x86/entry: Add the C version ist_restore_cr3() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 20/24] x86/entry: Add the C version get_percpu_base() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 21/24] x86/entry: Add the C version ist_switch_to_kernel_gsbase() Lai Jiangshan
2021-08-31 17:50 ` [PATCH 22/24] x86/entry: Implement and use do_paranoid_entry() and paranoid_exit() Lai Jiangshan
2021-09-02 10:33   ` Peter Zijlstra
2021-09-02 10:42     ` Lai Jiangshan
2021-09-02 12:02       ` Peter Zijlstra
2021-09-02 11:58     ` Lai Jiangshan
2021-09-02 12:29       ` Joerg Roedel
2021-08-31 17:50 ` [PATCH 23/24] x86/entry: Remove the unused ASM macros Lai Jiangshan
2021-08-31 17:50 ` [PATCH 24/24] x86/syscall/64: Move the checking for sysret to C code Lai Jiangshan
2021-09-10  7:20   ` Nikolay Borisov
2021-09-10  7:30     ` Lai Jiangshan
2021-08-31 20:44 ` [PATCH 00/24] x86/entry/64: Convert a bunch of ASM entry code into " Peter Zijlstra
2021-09-02  6:28   ` Lai Jiangshan
2021-09-02  7:44     ` Peter Zijlstra
2021-09-02 10:50 ` [PATCH 25/24] x86/traps: Rewrite native_load_gs_index in " Lai Jiangshan
2021-09-08  1:38   ` H. Peter Anvin
2021-09-08  4:42     ` H. Peter Anvin
2021-09-08  5:00       ` H. Peter Anvin
2021-09-08  7:12         ` Lai Jiangshan
2021-09-09 23:16           ` H. Peter Anvin
2021-09-13 20:01   ` Andy Lutomirski
2021-09-14  2:04     ` Lai Jiangshan
2021-09-14  8:14       ` Peter Zijlstra
2021-09-14  8:17         ` Borislav Petkov
2021-09-14  8:40         ` Lai Jiangshan

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